1
|
Stamatopoulou V, Akoumianaki E, Vaporidi K, Stamatopoulos E, Kondili E, Georgopoulos D. Driving pressure of respiratory system and lung stress in mechanically ventilated patients with active breathing. Crit Care 2024; 28:19. [PMID: 38217038 PMCID: PMC10785492 DOI: 10.1186/s13054-024-04797-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 01/03/2024] [Indexed: 01/14/2024] Open
Abstract
BACKGROUND During control mechanical ventilation (CMV), the driving pressure of the respiratory system (ΔPrs) serves as a surrogate of transpulmonary driving pressure (ΔPlung). Expiratory muscle activity that decreases end-expiratory lung volume may impair the validity of ΔPrs to reflect ΔPlung. This prospective observational study in patients with acute respiratory distress syndrome (ARDS) ventilated with proportional assist ventilation (PAV+), aimed to investigate: (1) the prevalence of elevated ΔPlung, (2) the ΔPrs-ΔPlung relationship, and (3) whether dynamic transpulmonary pressure (Plungsw) and effort indices (transdiaphragmatic and respiratory muscle pressure swings) remain within safe limits. METHODS Thirty-one patients instrumented with esophageal and gastric catheters (n = 22) were switched from CMV to PAV+ and respiratory variables were recorded, over a maximum of 24 h. To decrease the contribution of random breaths with irregular characteristics, a 7-breath moving average technique was applied. In each patient, measurements were also analyzed per deciles of increasing lung elastance (Elung). Patients were divided into Group A, if end-inspiratory transpulmonary pressure (PLEI) increased as Elung increased, and Group B, which showed a decrease or no change in PLEI with Elung increase. RESULTS In 44,836 occluded breaths, ΔPlung ≥ 12 cmH2O was infrequently observed [0.0% (0.0-16.9%) of measurements]. End-expiratory lung volume decrease, due to active expiration, was associated with underestimation of ΔPlung by ΔPrs, as suggested by a negative linear relationship between transpulmonary pressure at end-expiration (PLEE) and ΔPlung/ΔPrs. Group A included 17 and Group B 14 patients. As Elung increased, ΔPlung increased mainly due to PLEI increase in Group A, and PLEE decrease in Group B. Although ΔPrs had an area receiver operating characteristic curve (AUC) of 0.87 (95% confidence intervals 0.82-0.92, P < 0.001) for ΔPlung ≥ 12 cmH2O, this was due exclusively to Group A [0.91 (0.86-0.95), P < 0.001]. In Group B, ΔPrs showed no predictive capacity for detecting ΔPlung ≥ 12 cmH2O [0.65 (0.52-0.78), P > 0.05]. Most of the time Plungsw and effort indices remained within safe range. CONCLUSION In patients with ARDS ventilated with PAV+, injurious tidal lung stress and effort were infrequent. In the presence of expiratory muscle activity, ΔPrs underestimated ΔPlung. This phenomenon limits the usefulness of ΔPrs as a surrogate of tidal lung stress, regardless of the mode of support.
Collapse
Affiliation(s)
- Vaia Stamatopoulou
- Intensive Care Medicine Department, University Hospital of Heraklion, Heraklion, Crete, Greece
| | - Evangelia Akoumianaki
- Intensive Care Medicine Department, University Hospital of Heraklion, Heraklion, Crete, Greece
- Medical School, University of Crete, Heraklion, Crete, Greece
| | - Katerina Vaporidi
- Intensive Care Medicine Department, University Hospital of Heraklion, Heraklion, Crete, Greece
- Medical School, University of Crete, Heraklion, Crete, Greece
| | - Efstathios Stamatopoulos
- Decision Support Systems, Laboratory, School of Electrical and Computer Engineering, National Technical University of Athens, Athens, Greece
| | - Eumorfia Kondili
- Intensive Care Medicine Department, University Hospital of Heraklion, Heraklion, Crete, Greece
- Medical School, University of Crete, Heraklion, Crete, Greece
| | - Dimitrios Georgopoulos
- Intensive Care Medicine Department, University Hospital of Heraklion, Heraklion, Crete, Greece.
- Medical School, University of Crete, Heraklion, Crete, Greece.
| |
Collapse
|
2
|
Matsumoto Y, Obara S, Hakozaki T, Isosu T, Inoue S. The effects of chest drainage on pressure-controlled ventilation. JA Clin Rep 2022; 8:78. [PMID: 36190585 PMCID: PMC9530080 DOI: 10.1186/s40981-022-00568-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 09/26/2022] [Accepted: 09/27/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The use of pressure-controlled ventilation (PCV) for anesthesia management is becoming more commonly used. Chest drainage is commonly performed after thoracic surgery, and the negative pressure it generates might affect the transpulmonary pressure (TPP). In the present study, we investigated how chest drainage could affect ventilating conditions during PCV. METHODS We created a hand-made simple thoracic and lung model, which was connected to an anesthesia machine. The tidal volume (TV) was measured with positive end-expiratory pressure (PEEP) 0 and no chest drainage (baseline), followed by 10 cmH2O PEEP/no drainage, 10 cmH2O PEEP/drainage with - 10 cmH2O and 10 cmH2O PEEP/drainage with - 20 cmH2O. Finally, TV with 20 cmH2O and 30 cmH2O PEEP/no drainage was measured. Driving (inspiratory) pressure was maintained at 20 cmH2O during the whole experiment. RESULTS TV was significantly increased by applying 10 cmH2O PEEP compared with baseline, further increased by applying - 10 cmH2O by drainage, similar to the value with PEEP 20 cmH2O with no drainage (end-tidal TPP of 20 cmH2O for both). TV decreased to < 50% of the baseline by applying 10 cmH2O PEEP with - 20 cmH2O by drainage, which was similar to that with 30 cmH2O PEEP with no drainage (end-tidal TPP of 30 cmH2O for both). CONCLUSIONS TV was maintained at similar levels with the same TPP, regardless of PEEP or negative pressure by chest drainage change, suggesting that negative intrapleural pressure by the chest tube drainage system might mimic PEEP from the point of TV.
Collapse
Affiliation(s)
- Yuko Matsumoto
- grid.411582.b0000 0001 1017 9540Department of Anesthesiology and Division of Intensive Care, Fukushima Medical University, 1 Hikarigaoka, Fukushima, Fukushima 960-1295 Japan
| | - Shinju Obara
- grid.411582.b0000 0001 1017 9540Department of Anesthesiology and Division of Intensive Care, Fukushima Medical University, 1 Hikarigaoka, Fukushima, Fukushima 960-1295 Japan
| | - Takahiro Hakozaki
- grid.411582.b0000 0001 1017 9540Department of Anesthesiology and Division of Intensive Care, Fukushima Medical University, 1 Hikarigaoka, Fukushima, Fukushima 960-1295 Japan
| | - Tsuyoshi Isosu
- grid.411582.b0000 0001 1017 9540Department of Anesthesiology and Division of Intensive Care, Fukushima Medical University, 1 Hikarigaoka, Fukushima, Fukushima 960-1295 Japan
| | - Satoki Inoue
- grid.411582.b0000 0001 1017 9540Department of Anesthesiology and Division of Intensive Care, Fukushima Medical University, 1 Hikarigaoka, Fukushima, Fukushima 960-1295 Japan
| |
Collapse
|
3
|
Drevhammar T, Falk M, Donaldsson S, Tracy M, Hinder M. Neonatal Resuscitation With T-Piece Systems: Risk of Inadvertent PEEP Related to Mechanical Properties. Front Pediatr 2021; 9:663249. [PMID: 34164358 PMCID: PMC8215339 DOI: 10.3389/fped.2021.663249] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 05/14/2021] [Indexed: 11/25/2022] Open
Abstract
Background: Resuscitation of infants using T-piece resuscitators (TPR) allow positive pressure ventilation with positive end-expiratory pressure (PEEP). The adjustable PEEP valve adds resistance to expiration and could contribute to inadvertent PEEP. The study indirectly investigated risk of inadvertent peep by determining expiratory time constants. The aim was to measure system expiratory time constants for a TPR device in a passive mechanical model with infant lung properties. Methods: We used adiabatic bottles to generate four levels of compliance (0.5-3.4 mL/cm H2O). Expiratory time constants were recorded for combinations of fresh gas flow (8, 10, 15 L/min), PEEP (5, 8, 10 cm H2O), airway resistance (50, 200 cm H2O/L/sec and none), endotracheal tube (none, size 2.5, 3.0, 3.5) with a peak inflation pressure of 15 cm H2O above PEEP. Results: Low compliances resulted in time constants below 0.17 s contrasting to higher compliances where the expiratory time constants were 0.25-0.81 s. Time constants increased with increased resistance, lower fresh gas flows, higher set PEEP levels and with an added airway resistance or endotracheal tube. Conclusions: The risk of inadvertent PEEP increases with a shorter time for expiration in combination with a higher compliance or resistance. The TPR resistance can be reduced by increasing the fresh gas flow or reducing PEEP. The expiratory time constants indicate that this may be clinically important. The risk of inadvertent PEEP would be highest in intubated term infants with highly compliant lungs. These results are useful for interpreting clinical events and recordings.
Collapse
Affiliation(s)
- Thomas Drevhammar
- Anaesthesiology and Intensive Care Medicine, Department of Surgical and Perioperative Sciences, Umeå University, Umeå, Sweden
| | - Markus Falk
- Department of Women's and Children's Health, Karolinska Institute, Stockholm, Sweden
| | - Snorri Donaldsson
- Department of Women's and Children's Health, Karolinska Institute, Stockholm, Sweden.,Neonatology Department, Karolinska University Hospital, Stockholm, Sweden
| | - Mark Tracy
- Department of Pediatrics and Child Health, The University of Sydney, Sydney, NSW, Australia.,Neonatal Intensive Care Unit, Westmead Hospital, Sydney, NSW, Australia
| | - Murray Hinder
- Department of Pediatrics and Child Health, The University of Sydney, Sydney, NSW, Australia.,Neonatal Intensive Care Unit, Westmead Hospital, Sydney, NSW, Australia
| |
Collapse
|
4
|
Gudmundsson M, Persson P, Perchiazzi G, Lundin S, Rylander C. Transpulmonary driving pressure during mechanical ventilation-validation of a non-invasive measurement method. Acta Anaesthesiol Scand 2020; 64:211-215. [PMID: 31585019 DOI: 10.1111/aas.13482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 08/27/2019] [Accepted: 09/15/2019] [Indexed: 11/29/2022]
Abstract
BACKGROUND Transpulmonary driving pressure plays an important role in today's understanding of ventilator induced lung injury. We have previously validated a novel non-invasive method based on stepwise increments of PEEP to assess transpulmonary driving pressure in anaesthetised patients with healthy lungs. The aim of this study was to validate the method in patients who were mechanically ventilated for different diagnoses requiring intensive care. METHODS We measured transpulmonary pressure (Ptp) and calculated transpulmonary driving pressure (ΔPtp) in 31 patients undergoing mechanical ventilation in an intensive care unit. Parallel triplicate measurements were performed with the PEEP step method (PtpPSM) and the conventional oesophageal balloon method (Ptpconv). Their agreement was compared using the intraclass correlation coefficient (ICC) and the Bland Altman plot. RESULT The coefficient of variation for the repeated measurements was 4,3 for ΔPtpPSM and 9,2 for ΔPtpconv. The ICC of 0,864 and the Bland Altman plot indicate good agreement between the two methods. CONCLUSION The non-invasive method can be applied in mechanically ventilated patients to measure transpulmonary driving pressure with good repeatability and accuracy comparable to the traditional oesophageal balloon method.
Collapse
Affiliation(s)
- Magni Gudmundsson
- Department of Anaesthesiology and Intensive Care Medicine, Institute of Clinical Sciences, Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
| | - Per Persson
- Department of Anaesthesiology and Intensive Care Medicine, Institute of Clinical Sciences, Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
| | - Gaetano Perchiazzi
- Hedenstierna Laboratory, Institute of Medical Sciences Uppsala University Uppsala Sweden
| | - Stefan Lundin
- Department of Anaesthesiology and Intensive Care Medicine, Institute of Clinical Sciences, Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
| | - Christian Rylander
- Department of Anaesthesiology and Intensive Care Medicine, Institute of Clinical Sciences, Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
| |
Collapse
|
5
|
Umbrello M, Chiumello D. Interpretation of the transpulmonary pressure in the critically ill patient. ANNALS OF TRANSLATIONAL MEDICINE 2018; 6:383. [PMID: 30460257 DOI: 10.21037/atm.2018.05.31] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Mechanical ventilation is a life-saving procedure, which takes over the function of the respiratory muscles while buying time for healing to take place. However, it can also promote or worsen lung injury, so that careful monitoring of respiratory mechanics is suggested to titrate the level of support and avoid injurious pressures and volumes to develop. Standard monitoring includes flow, volume and airway pressure (Paw). However, Paw represents the pressure acting on the respiratory system as a whole, and does not allow to differentiate the part of pressure that is spent di distend the chest wall. Moreover, if spontaneous breathing efforts are allowed, the Paw is the sum of that applied by the ventilator and that generated by the patient. As a consequence, monitoring of Paw has significant shortcomings. Assessment of esophageal pressure (Pes), as a surrogate for pleural pressure (Ppl), may allow the clinicians to discriminate between the elastic behaviour of the lung and the chest wall, and to calculate the degree of spontaneous respiratory effort. In the present review, the characteristics and limitations of airway and transpulmonary pressure monitoring will be presented; we will highlight the different assumptions underlying the various methods for measuring transpulmonary pressure (i.e., the elastance-derived and the release-derived method, and the direct measurement), as well as the potential application of transpulmonary pressure assessment during both controlled and spontaneous/assisted mechanical ventilation in critically ill patients.
Collapse
Affiliation(s)
- Michele Umbrello
- UOC Anestesia e Rianimazione, Ospedale San Paolo - ASST Santi Paolo e Carlo, Milano, Italy
| | - Davide Chiumello
- UOC Anestesia e Rianimazione, Ospedale San Paolo - ASST Santi Paolo e Carlo, Milano, Italy.,Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milano, Italy
| |
Collapse
|
6
|
Gudmundsson M, Perchiazzi G, Pellegrini M, Vena A, Hedenstierna G, Rylander C. Atelectasis is inversely proportional to transpulmonary pressure during weaning from ventilator support in a large animal model. Acta Anaesthesiol Scand 2018; 62:94-104. [PMID: 29058315 DOI: 10.1111/aas.13015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 09/22/2017] [Accepted: 09/30/2017] [Indexed: 01/27/2023]
Abstract
BACKGROUND In mechanically ventilated, lung injured, patients without spontaneous breathing effort, atelectasis with shunt and desaturation may appear suddenly when ventilator pressures are decreased. It is not known how such a formation of atelectasis is related to transpulmonary pressure (PL ) during weaning from mechanical ventilation when the spontaneous breathing effort is increased. If the relation between PL and atelectasis were known, monitoring of PL might help to avoid formation of atelectasis and cyclic collapse during weaning. The main purpose of this study was to determine the relation between PL and atelectasis in an experimental model representing weaning from mechanical ventilation. METHODS Dynamic transverse computed tomography scans were acquired in ten anaesthetized, surfactant-depleted pigs with preserved spontaneous breathing, as ventilator support was lowered by sequentially reducing inspiratory pressure and positive end expiratory pressure in steps. The volumes of gas and atelectasis in the lungs were correlated with PL obtained using oesophageal pressure recordings. Work of breathing (WOB) was assessed from Campbell diagrams. RESULTS Gradual decrease in PL in both end-expiration and end-inspiration caused a proportional increase in atelectasis and decrease in the gas content (linear mixed model with an autoregressive correlation matrix; P < 0.001) as the WOB increased. However, cyclic alveolar collapse during tidal ventilation did not increase significantly. CONCLUSION We found a proportional correlation between atelectasis and PL during the 'weaning process' in experimental mild lung injury. If confirmed in the clinical setting, a gradual tapering of ventilator support can be recommended for weaning without risk of sudden formation of atelectasis.
Collapse
Affiliation(s)
- M. Gudmundsson
- Department of Anaesthesiology and Intensive Care Medicine; Institute of Clinical Sciences; Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden
| | - G. Perchiazzi
- Hedenstierna Laboratory; Institute of Medical Sciences; Uppsala University; Uppsala Sweden
| | - M. Pellegrini
- Hedenstierna Laboratory; Institute of Medical Sciences; Uppsala University; Uppsala Sweden
| | - A. Vena
- Department of Emergency and Organ Transplant; Bari University; Bari Italy
| | - G. Hedenstierna
- Hedenstierna Laboratory; Institute of Medical Sciences; Uppsala University; Uppsala Sweden
| | - C. Rylander
- Department of Anaesthesiology and Intensive Care Medicine; Institute of Clinical Sciences; Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden
- Hedenstierna Laboratory; Institute of Medical Sciences; Uppsala University; Uppsala Sweden
| |
Collapse
|
7
|
Yoshida T, Nakahashi S, Nakamura MAM, Koyama Y, Roldan R, Torsani V, De Santis RR, Gomes S, Uchiyama A, Amato MBP, Kavanagh BP, Fujino Y. Volume-controlled Ventilation Does Not Prevent Injurious Inflation during Spontaneous Effort. Am J Respir Crit Care Med 2017; 196:590-601. [PMID: 28212050 DOI: 10.1164/rccm.201610-1972oc] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
RATIONALE Spontaneous breathing during mechanical ventilation increases transpulmonary pressure and Vt, and worsens lung injury. Intuitively, controlling Vt and transpulmonary pressure might limit injury caused by added spontaneous effort. OBJECTIVES To test the hypothesis that, during spontaneous effort in injured lungs, limitation of Vt and transpulmonary pressure by volume-controlled ventilation results in less injurious patterns of inflation. METHODS Dynamic computed tomography was used to determine patterns of regional inflation in rabbits with injured lungs during volume-controlled or pressure-controlled ventilation. Transpulmonary pressure was estimated by using esophageal balloon manometry [Pl(es)] with and without spontaneous effort. Local dependent lung stress was estimated as the swing (inspiratory change) in transpulmonary pressure measured by intrapleural manometry in dependent lung and was compared with the swing in Pl(es). Electrical impedance tomography was performed to evaluate the inflation pattern in a larger animal (pig) and in a patient with acute respiratory distress syndrome. MEASUREMENTS AND MAIN RESULTS Spontaneous breathing in injured lungs increased Pl(es) during pressure-controlled (but not volume-controlled) ventilation, but the pattern of dependent lung inflation was the same in both modes. In volume-controlled ventilation, spontaneous effort caused greater inflation and tidal recruitment of dorsal regions (greater than twofold) compared with during muscle paralysis, despite the same Vt and Pl(es). This was caused by higher local dependent lung stress (measured by intrapleural manometry). In injured lungs, esophageal manometry underestimated local dependent pleural pressure changes during spontaneous effort. CONCLUSIONS Limitation of Vt and Pl(es) by volume-controlled ventilation could not eliminate harm caused by spontaneous breathing unless the level of spontaneous effort was lowered and local dependent lung stress was reduced.
Collapse
Affiliation(s)
- Takeshi Yoshida
- 1 Intensive Care Unit, Osaka University Hospital, Suita, Japan.,2 Translational Medicine, Department of Critical Care Medicine and Department of Anesthesia, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Susumu Nakahashi
- 1 Intensive Care Unit, Osaka University Hospital, Suita, Japan.,3 Emergency and Critical Care Center, Mie University Hospital, Tsu, Japan
| | - Maria Aparecida Miyuki Nakamura
- 4 Laboratório de Pneumologia LIM-09, Disciplina de Pneumologia, Instituto do Coração (Incor), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil; and
| | - Yukiko Koyama
- 1 Intensive Care Unit, Osaka University Hospital, Suita, Japan
| | - Rollin Roldan
- 4 Laboratório de Pneumologia LIM-09, Disciplina de Pneumologia, Instituto do Coração (Incor), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil; and.,5 Unidad de Cuidados Intensivos, Hospital Rebagliati, Lima, Peru
| | - Vinicius Torsani
- 4 Laboratório de Pneumologia LIM-09, Disciplina de Pneumologia, Instituto do Coração (Incor), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil; and
| | - Roberta R De Santis
- 4 Laboratório de Pneumologia LIM-09, Disciplina de Pneumologia, Instituto do Coração (Incor), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil; and
| | - Susimeire Gomes
- 4 Laboratório de Pneumologia LIM-09, Disciplina de Pneumologia, Instituto do Coração (Incor), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil; and
| | | | - Marcelo B P Amato
- 4 Laboratório de Pneumologia LIM-09, Disciplina de Pneumologia, Instituto do Coração (Incor), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil; and
| | - Brian P Kavanagh
- 2 Translational Medicine, Department of Critical Care Medicine and Department of Anesthesia, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Yuji Fujino
- 1 Intensive Care Unit, Osaka University Hospital, Suita, Japan
| |
Collapse
|
8
|
Mohammad HA, Ali WA. Predictive value of EndTidalCO2, lung mechanics and other standard parameters for weaning neurological patients from mechanical ventilation. EGYPTIAN JOURNAL OF CHEST DISEASES AND TUBERCULOSIS 2016. [DOI: 10.1016/j.ejcdt.2015.10.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
|
9
|
Agmy GR, Mohammad HA, Hassanin AAM. The prognostic value of the dead-space fraction and other physiological parameters in the weaning process of mechanical ventilation in patients with obstructive air flow. THE EGYPTIAN JOURNAL OF BRONCHOLOGY 2015. [DOI: 10.4103/1687-8426.165902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
|
10
|
Beda A, Güldner A, Carvalho AR, Zin WA, Carvalho NC, Huhle R, Giannella-Neto A, Koch T, de Abreu MG. Liquid- and air-filled catheters without balloon as an alternative to the air-filled balloon catheter for measurement of esophageal pressure. PLoS One 2014; 9:e103057. [PMID: 25247308 PMCID: PMC4172426 DOI: 10.1371/journal.pone.0103057] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 06/26/2014] [Indexed: 11/25/2022] Open
Abstract
Background Measuring esophageal pressure (Pes) using an air-filled balloon catheter (BC) is the common approach to estimate pleural pressure and related parameters. However, Pes is not routinely measured in mechanically ventilated patients, partly due to technical and practical limitations and difficulties. This study aimed at comparing the conventional BC with two alternative methods for Pes measurement, liquid-filled and air-filled catheters without balloon (LFC and AFC), during mechanical ventilation with and without spontaneous breathing activity. Seven female juvenile pigs (32–42 kg) were anesthetized, orotracheally intubated, and a bundle of an AFC, LFC, and BC was inserted in the esophagus. Controlled and assisted mechanical ventilation were applied with positive end-expiratory pressures of 5 and 15 cmH2O, and driving pressures of 10 and 20 cmH2O, in supine and lateral decubitus. Main Results Cardiogenic noise in BC tracings was much larger (up to 25% of total power of Pes signal) than in AFC and LFC (<3%). Lung and chest wall elastance, pressure-time product, inspiratory work of breathing, inspiratory change and end-expiratory value of transpulmonary pressure were estimated. The three catheters allowed detecting similar changes in these parameters between different ventilation settings. However, a non-negligible and significant bias between estimates from BC and those from AFC and LFC was observed in several instances. Conclusions In anesthetized and mechanically ventilated pigs, the three catheters are equivalent when the aim is to detect changes in Pes and related parameters between different conditions, but possibly not when the absolute value of the estimated parameters is of paramount importance. Due to a better signal-to-noise ratio, and considering its practical advantages in terms of easier calibration and simpler acquisition setup, LFC may prove interesting for clinical use.
Collapse
Affiliation(s)
- Alessandro Beda
- Pulmonary Engineering Group, Clinic of Anaesthesiology and Intensive Care Therapy, University Hospital Dresden, Technische Universität Dresden, Dresden, Germany
- Department of Electronic Engineering and Postgraduate Program of Electrical Engineering, Federal University of Minas Gerais, Pampulha, Belo Horizonte, Brazil
- * E-mail:
| | - Andreas Güldner
- Pulmonary Engineering Group, Clinic of Anaesthesiology and Intensive Care Therapy, University Hospital Dresden, Technische Universität Dresden, Dresden, Germany
| | - Alysson R. Carvalho
- Laboratory of Respiration Physiology, Carlos Chagas Filho Biophysics Institute, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Biomedical Engineering Program, Alberto Luis Coimbra Program of Post-Graduation and Research in Engineering, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Walter Araujo Zin
- Laboratory of Respiration Physiology, Carlos Chagas Filho Biophysics Institute, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Nadja C. Carvalho
- Pulmonary Engineering Group, Clinic of Anaesthesiology and Intensive Care Therapy, University Hospital Dresden, Technische Universität Dresden, Dresden, Germany
- Department of Electronic Engineering and Postgraduate Program of Electrical Engineering, Federal University of Minas Gerais, Pampulha, Belo Horizonte, Brazil
| | - Robert Huhle
- Pulmonary Engineering Group, Clinic of Anaesthesiology and Intensive Care Therapy, University Hospital Dresden, Technische Universität Dresden, Dresden, Germany
| | - Antonio Giannella-Neto
- Biomedical Engineering Program, Alberto Luis Coimbra Program of Post-Graduation and Research in Engineering, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Thea Koch
- Pulmonary Engineering Group, Clinic of Anaesthesiology and Intensive Care Therapy, University Hospital Dresden, Technische Universität Dresden, Dresden, Germany
| | - Marcelo Gama de Abreu
- Pulmonary Engineering Group, Clinic of Anaesthesiology and Intensive Care Therapy, University Hospital Dresden, Technische Universität Dresden, Dresden, Germany
| |
Collapse
|
11
|
Guo R, Fan E. Beyond low tidal volumes: ventilating the patient with acute respiratory distress syndrome. Clin Chest Med 2014; 35:729-41. [PMID: 25453421 DOI: 10.1016/j.ccm.2014.08.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The cornerstone of lung protective ventilation in patients with acute respiratory distress syndrome (ARDS) is a pressure- and volume-limited strategy. Other interventions have also been investigated. Although no method for positive end-expiratory pressure (PEEP) titration has proven most advantageous, experimental and clinical data support the use of higher PEEP in patients with moderate/severe ARDS. There is no benefit to the early use of high-frequency oscillatory ventilation (HFOV) in patients with moderate/severe ARDS, although it may be considered as rescue therapy. Further investigations of novel methods of bedside monitoring of mechanical ventilation may help identify the optimal ventilatory strategy.
Collapse
Affiliation(s)
- Ray Guo
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Eddy Fan
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada.
| |
Collapse
|
12
|
The assessment of transpulmonary pressure in mechanically ventilated ARDS patients. Intensive Care Med 2014; 40:1670-8. [PMID: 25112501 DOI: 10.1007/s00134-014-3415-4] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 07/19/2014] [Indexed: 10/24/2022]
Abstract
PURPOSE The optimal method for estimating transpulmonary pressure (i.e. the fraction of the airway pressure transmitted to the lung) has not yet been established. METHODS In this study on 44 patients with acute respiratory distress syndrome (ARDS), we computed the end-inspiratory transpulmonary pressure as the change in airway and esophageal pressure from end-inspiration to atmospheric pressure (i.e. release derived) and as the product of the end-inspiratory airway pressure and the ratio of lung to respiratory system elastance (i.e. elastance derived). The end-expiratory transpulmonary pressure was estimated as the product of positive end-expiratory pressure (PEEP) minus the direct measurement of esophageal pressure and by the release method. RESULTS The mean elastance- and release-derived transpulmonary pressure were 14.4 ± 3.7 and 14.4 ± 3.8 cmH₂O at 5 cmH₂O of PEEP and 21.8 ± 5.1 and 21.8 ± 4.9 cmH₂O at 15 cmH₂O of PEEP, respectively (P = 0.32, P = 0.98, respectively), indicating that these parameters were significantly related (r(2) = 0.98, P < 0.001 at 5 cmH₂O of PEEP; r(2) = 0.93, P < 0.001 at 15 cmH₂O of PEEP). The percentage error was 5.6 and 12.0 %, respectively. The mean directly measured and release-derived transpulmonary pressure were -8.0 ± 3.8 and 3.9 ± 0.9 cmH₂O at 5 cmH₂O of PEEP and -1.2 ± 3.2 and 10.6 ± 2.2 cmH₂O at 15 cmH₂O of PEEP, respectively, indicating that these parameters were not related (r(2) = 0.07, P = 0.08 at 5 cmH₂O of PEEP; r (2) = 0.10, P = 0.53 at 15 cmH₂O of PEEP). CONCLUSIONS Based on our observations, elastance-derived transpulmonary pressure can be considered to be an adequate surrogate of the release-derived transpulmonary pressure, while the release-derived and directly measured end-expiratory transpulmonary pressure are not related.
Collapse
|
13
|
Airway pressure and transpulmonary pressure during high-frequency oscillation for acute respiratory distress syndrome. Can Respir J 2013; 21:107-11. [PMID: 24137575 DOI: 10.1155/2014/163293] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND High-frequency oscillation (HFO) is used for the treatment of refractory hypoxic respiratory failure. OBJECTIVE To demonstrate that the mean transpulmonary pressure (PL) cannot be inferred from mean airway pressure (mPaw). METHODS In seven patients already undergoing HFO for refractory acute respiratory distress syndrome, esophageal pressure (Pes) was measured using an esophageal balloon catheter. Pleural pressure (Ppl) and PL were calculated from Pes. MAIN RESULTS In the seven patients (mean [± SD] age 59 ± 9 years) treated with HFO at 5 ± 1 Hz and amplitude 75 ± 10 cmH2O, the mPaw was 27 ± 6 cmH2O, Ppl was 9 ± 6 cmH2O and PL was 18 ± 11 cmH2O. Successful catheter placement and measurement of Pes occurred in 100% of subjects. There was no correlation between PL and mPaw. The majority of subjects required hemodynamic support during the use of HFO; the frequency and degree of support during the study period was no different than that before the study. CONCLUSION The present report is the first to describe measuring Pes and calculating Ppl during HFO for acute respiratory distress syndrome. While both current guidelines and recent trials have titrated treatment based on mPaw and oxygenation, there is wide variability in PL during HFO and PL cannot be predicted from mPaw.
Collapse
|
14
|
Liu Q, Li W, Zeng QS, Zhong NS, Chen RC. Lung stress and strain during mechanical ventilation in animals with and without pulmonary acute respiratory distress syndrome. J Surg Res 2013; 181:300-7. [DOI: 10.1016/j.jss.2012.07.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 06/19/2012] [Accepted: 07/03/2012] [Indexed: 11/27/2022]
|
15
|
Pecchiari M, Loring SH, D’Angelo E. Esophageal pressure as an estimate of average pleural pressure with lung or chest distortion in rats. Respir Physiol Neurobiol 2013; 186:229-35. [DOI: 10.1016/j.resp.2013.02.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Revised: 01/30/2013] [Accepted: 02/01/2013] [Indexed: 01/18/2023]
|
16
|
Nassar BS, Collett ND, Schmidt GA. The flow-time waveform predicts respiratory system resistance and compliance. J Crit Care 2012; 27:418.e7-14. [PMID: 22226421 DOI: 10.1016/j.jcrc.2011.10.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Revised: 09/28/2011] [Accepted: 10/31/2011] [Indexed: 02/09/2023]
Abstract
PURPOSE Knowledge of patients' lung compliance and resistance aids clinical management. We investigated whether these values, readily measured during volume assist-control ventilation (VACV), could also be estimated during pressure assist-control ventilation (PACV). METHODS Data were collected in 12 mechanically ventilated human subjects. During VACV, peak pressure, plateau pressure, end-expiratory pressure, tidal volume, and inspiratory flow rate were measured. During PACV, inspiratory pressure, end-expiratory pressure, and tidal volume were recorded. The linear component of the pressure-time waveform was extrapolated to time and flow axes. Using the equation of motion for the respiratory system, assuming a nonlinear resistance, we calculated inspiratory resistance and compliance. During VACV, compliance and inspiratory resistance were calculated in the conventional manner. RESULTS In ventilated subjects, mean compliance during PACV was 37.06 ± 15.65 mL/cm H(2)O, and during VACV, 36.93 ± 12.18 mL/cm H(2)O. Mean inspiratory resistance during PACV was 15.17 ± 5.14 cm H(2)O/L per second, whereas during VACV, it was 12.50 ± 2.99 cm H(2)O/L per second. A strong correlation is evident between compliance and inspiratory resistance calculated during PACV vs VACV (r(2) of 0.73 and 0.51, respectively). CONCLUSIONS During PACV, the inspiratory flow waveform is linear, and its slope contains information regarding inspiratory resistance and compliance. Calculated values correlate with those during VACV.
Collapse
Affiliation(s)
- Boulos S Nassar
- Division of Pulmonary, Critical Care, and Occupational Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA.
| | | | | |
Collapse
|
17
|
Henderson WR, Sheel AW. Pulmonary mechanics during mechanical ventilation. Respir Physiol Neurobiol 2011; 180:162-72. [PMID: 22154694 DOI: 10.1016/j.resp.2011.11.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Revised: 11/16/2011] [Accepted: 11/23/2011] [Indexed: 10/14/2022]
Abstract
The use of mechanical ventilation has become widespread in the management of hypoxic respiratory failure. Investigations of pulmonary mechanics in this clinical scenario have demonstrated that there are significant differences in compliance, resistance and gas flow when compared with normal subjects. This paper will review the mechanisms by which pulmonary mechanics are assessed in mechanically ventilated patients and will review how the data can be used for investigative research purposes as well as to inform rational ventilator management.
Collapse
Affiliation(s)
- William R Henderson
- Program of Critical Care Medicine, University of British Columbia, Vancouver, BC, Canada.
| | | |
Collapse
|
18
|
Abstract
PURPOSE OF REVIEW Despite the well recognized role of mechanical ventilation in lung injury, appropriate surrogate markers to guide titration of ventilator settings remain elusive. One would like to strike a balance between protecting aerated units from overdistension while recruiting unstable units, thereby reducing tissue damage associated with their cyclic recruitment and derecruitment. To do so requires some estimate of the topographical distribution of parenchymal stress and strain. RECENT FINDINGS Recent studies have highlighted the importance of chest wall recoil and its effect on pleural pressure (Ppl) in determining lung stress. Although esophageal pressure (Pes) has traditionally been used to measure the average Ppl in normal upright patients, in recumbent acute lung injury/acute respiratory distress syndrome patients Pes-based estimates of Ppl are subject to untestable assumptions. Nevertheless, Pes measurements in recumbent patients with injured lungs strongly suggest that Ppl over dependent parts of the lung can exceed airway pressure by substantial amounts. Moreover, results of a pilot study in which Pes was used to titrate positive end-expiratory pressure (PEEP) suggest clinical benefit. SUMMARY Notwithstanding its theoretical limitations, esophageal manometry has shown promise in PEEP titration and deserves further evaluation in a larger trial on patients with injured lungs.
Collapse
Affiliation(s)
- Maria Plataki
- Thoracic Diseases Research Unit, Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA
| | | |
Collapse
|
19
|
On-line monitoring of lung mechanics during spontaneous breathing: a physiological study. Respir Med 2010; 104:463-71. [DOI: 10.1016/j.rmed.2009.09.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Revised: 09/20/2009] [Accepted: 09/22/2009] [Indexed: 11/17/2022]
|
20
|
|
21
|
Loring SH, O'Donnell CR, Behazin N, Malhotra A, Sarge T, Ritz R, Novack V, Talmor D. Esophageal pressures in acute lung injury: do they represent artifact or useful information about transpulmonary pressure, chest wall mechanics, and lung stress? J Appl Physiol (1985) 2009; 108:515-22. [PMID: 20019160 DOI: 10.1152/japplphysiol.00835.2009] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Acute lung injury can be worsened by inappropriate mechanical ventilation, and numerous experimental studies suggest that ventilator-induced lung injury is increased by excessive lung inflation at end inspiration or inadequate lung inflation at end expiration. Lung inflation depends not only on airway pressures from the ventilator but, also, pleural pressure within the chest wall. Although esophageal pressure (Pes) measurements are often used to estimate pleural pressures in healthy subjects and patients, they are widely mistrusted and rarely used in critical illness. To assess the credibility of Pes as an estimate of pleural pressure in critically ill patients, we compared Pes measurements in 48 patients with acute lung injury with simultaneously measured gastric and bladder pressures (Pga and P(blad)). End-expiratory Pes, Pga, and P(blad) were high and varied widely among patients, averaging 18.6 +/- 4.7, 18.4 +/- 5.6, and 19.3 +/- 7.8 cmH(2)O, respectively (mean +/- SD). End-expiratory Pes was correlated with Pga (P = 0.0004) and P(blad) (P = 0.0104) and unrelated to chest wall compliance. Pes-Pga differences were consistent with expected gravitational pressure gradients and transdiaphragmatic pressures. Transpulmonary pressure (airway pressure - Pes) was -2.8 +/- 4.9 cmH(2)O at end exhalation and 8.3 +/- 6.2 cmH(2)O at end inflation, values consistent with effects of mediastinal weight, gravitational gradients in pleural pressure, and airway closure at end exhalation. Lung parenchymal stress measured directly as end-inspiratory transpulmonary pressure was much less than stress inferred from the plateau airway pressures and lung and chest wall compliances. We suggest that Pes can be used to estimate transpulmonary pressures that are consistent with known physiology and can provide meaningful information, otherwise unavailable, in critically ill patients.
Collapse
Affiliation(s)
- Stephen H Loring
- Department of Anesthesia, Critical Care, and Pain Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.
| | | | | | | | | | | | | | | |
Collapse
|
22
|
Yalcin HC, Hallow KM, Wang J, Wei MT, Ou-Yang HD, Ghadiali SN. Influence of cytoskeletal structure and mechanics on epithelial cell injury during cyclic airway reopening. Am J Physiol Lung Cell Mol Physiol 2009; 297:L881-91. [PMID: 19700641 DOI: 10.1152/ajplung.90562.2008] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Although patients with acute respiratory distress syndrome require mechanical ventilation, these ventilators often exacerbate the existing lung injury. For example, the cyclic closure and reopening of fluid-filled airways during ventilation can cause epithelial cell (EpC) necrosis and barrier disruption. Although much work has focused on minimizing the injurious mechanical forces generated during ventilation, an alternative approach is to make the EpC less susceptible to injury by altering the cell's intrinsic biomechanical/biostructural properties. In this study, we hypothesized that alterations in cytoskeletal structure and mechanics can be used to reduce the cell's susceptibility to injury during airway reopening. EpC were treated with jasplakinolide to stabilize actin filaments or latrunculin A to depolymerize actin and then exposed to cyclic airway reopening conditions at room temperature using a previously developed in vitro cell culture model. Actin stabilization did not affect cell viability but significantly improved cell adhesion primarily due to the development of more numerous focal adhesions. Surprisingly, actin depolymerization significantly improved both cell viability and cell adhesion but weakened focal adhesions. Optical tweezer based measurements of the EpC's micromechanical properties indicate that although latrunculin-treated cells are softer, they also have increased viscous damping properties. To further investigate the effect of "fluidization" on cell injury, experiments were also conducted at 37 degrees C. Although cells held at 37 degrees C exhibited no changes in cytoskeletal structure, they did exhibit increased viscous damping properties and improved cell viability. We conclude that fluidization of the actin cytoskeleton makes the EpC less susceptible to the injurious mechanical forces generated during cyclic airway reopening.
Collapse
Affiliation(s)
- H C Yalcin
- Mechanical Engineering and BioEngineering, Lehigh University, Bethlehem, PA, USA
| | | | | | | | | | | |
Collapse
|
23
|
Lefrant JY, De Backer D. Can we use pulse pressure variations to predict fluid responsiveness in patients with ARDS? Intensive Care Med 2009; 35:966-8. [DOI: 10.1007/s00134-009-1479-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2009] [Accepted: 03/12/2009] [Indexed: 11/29/2022]
|
24
|
Talmor D, Sarge T, Malhotra A, O'Donnell CR, Ritz R, Lisbon A, Novack V, Loring SH. Mechanical ventilation guided by esophageal pressure in acute lung injury. N Engl J Med 2008; 359:2095-104. [PMID: 19001507 PMCID: PMC3969885 DOI: 10.1056/nejmoa0708638] [Citation(s) in RCA: 665] [Impact Index Per Article: 41.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Survival of patients with acute lung injury or the acute respiratory distress syndrome (ARDS) has been improved by ventilation with small tidal volumes and the use of positive end-expiratory pressure (PEEP); however, the optimal level of PEEP has been difficult to determine. In this pilot study, we estimated transpulmonary pressure with the use of esophageal balloon catheters. We reasoned that the use of pleural-pressure measurements, despite the technical limitations to the accuracy of such measurements, would enable us to find a PEEP value that could maintain oxygenation while preventing lung injury due to repeated alveolar collapse or overdistention. METHODS We randomly assigned patients with acute lung injury or ARDS to undergo mechanical ventilation with PEEP adjusted according to measurements of esophageal pressure (the esophageal-pressure-guided group) or according to the Acute Respiratory Distress Syndrome Network standard-of-care recommendations (the control group). The primary end point was improvement in oxygenation. The secondary end points included respiratory-system compliance and patient outcomes. RESULTS The study reached its stopping criterion and was terminated after 61 patients had been enrolled. The ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen at 72 hours was 88 mm Hg higher in the esophageal-pressure-guided group than in the control group (95% confidence interval, 78.1 to 98.3; P=0.002). This effect was persistent over the entire follow-up time (at 24, 48, and 72 hours; P=0.001 by repeated-measures analysis of variance). Respiratory-system compliance was also significantly better at 24, 48, and 72 hours in the esophageal-pressure-guided group (P=0.01 by repeated-measures analysis of variance). CONCLUSIONS As compared with the current standard of care, a ventilator strategy using esophageal pressures to estimate the transpulmonary pressure significantly improves oxygenation and compliance. Multicenter clinical trials are needed to determine whether this approach should be widely adopted. (ClinicalTrials.gov number, NCT00127491.)
Collapse
Affiliation(s)
- Daniel Talmor
- Department of Anesthesia, Critical Care, and Pain Medicine, Beth Israel Deaconess Medical Center, Boston 02215, USA.
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Ghadiali SN, Gaver DP. Biomechanics of liquid-epithelium interactions in pulmonary airways. Respir Physiol Neurobiol 2008; 163:232-43. [PMID: 18511356 DOI: 10.1016/j.resp.2008.04.008] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2008] [Revised: 04/09/2008] [Accepted: 04/10/2008] [Indexed: 01/11/2023]
Abstract
The delicate structure of the lung epithelium makes it susceptible to surface tension induced injury. For example, the cyclic reopening of collapsed and/or fluid-filled airways during the ventilation of injured lungs generates hydrodynamic forces that further damage the epithelium and exacerbate lung injury. The interactions responsible for epithelial injury during airway reopening are fundamentally multiscale, since air-liquid interfacial dynamics affect global lung mechanics, while surface tension forces operate at the molecular and cellular scales. This article will review the current state-of-knowledge regarding the effect of surface tension forces on (a) the mechanics of airway reopening and (b) epithelial cell injury. Due to the complex nature of the liquid-epithelium system, a combination of computational and experimental techniques are being used to elucidate the mechanisms of surface-tension induced lung injury. Continued research is leading to an integrated understanding of the biomechanical and biological interactions responsible for cellular injury during airway reopening. This information may lead to novel therapies that minimize ventilation induced lung injury.
Collapse
Affiliation(s)
- Samir N Ghadiali
- Department of Mechanical Engineering and Mechanics, Bioengineering Program, Lehigh University, Bethlehem, PA 18015, USA.
| | | |
Collapse
|
26
|
Albaiceta GM, Blanch L, Lucangelo U. Static pressure–volume curves of the respiratory system: were they just a passing fad? Curr Opin Crit Care 2008; 14:80-6. [DOI: 10.1097/mcc.0b013e3282f2b8f4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
27
|
Talmor D, Sarge T, Legedza A, O'Donnell CR, Ritz R, Loring SH, Malhotra A. Cytokine release following recruitment maneuvers. Chest 2007; 132:1434-9. [PMID: 17925413 DOI: 10.1378/chest.07-1551] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND There are reports of rigors and/or clinical deterioration following recruitment maneuvers (RMs), leading us to question whether the use of sustained high-pressure inflation could lead to release of inflammatory mediators. METHODS Prospective cohort study of 26 patients with ARDS receiving mechanical ventilation. A single RM was performed during which the mean airway pressure was increased to 40 cm H2O and held constant for a period of 30 s. The concentration of nine cytokines (interleukin [IL]-1, IL-6, IL-8, IL-10, tumor necrosis factor [TNF]-alpha, Fas ligand, vascular endothelial growth factor, TNF receptor 1, TNF receptor 2) was measured longitudinally at three time points: prior to initiation of the RM, 5 min after the RM, and 60 min after the RM. RESULTS RMs were tolerated well from a hemodynamic perspective. Oxygenation improved as reflected by an increased Pao2/fraction of inspired oxygen (Fio2) ratio from 140+/-49 at baseline to 190+/-78 (mean+/-SD) at 5 min after the RM (p=0.01). At 60 min, the increase in Pao2/Fio2 ratio, to 172+/-76, was no longer significant (p=0.1). There were no important changes in the levels of any of the measured cytokines at 5 min or 60 min following RM as compared with the baseline levels. CONCLUSIONS The results of our study demonstrate that recruitment maneuvers are well tolerated in patients with ARDS. Our data suggest no major hemodynamic or immunologic evidence of deterioration within the first hour of RM. In particular, cytokines, previously related to worsening lung injury and distal organ failure in patients with ARDS, are not elevated by use of an RM. Registered at: www.clinicaltrials.gov as NCT00127491.
Collapse
Affiliation(s)
- Daniel Talmor
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, 1 Deaconess Rd, CC-470, Boston MA 02215, USA.
| | | | | | | | | | | | | |
Collapse
|
28
|
Karmrodt J, David M, Yuan S, Markstaller K. Alternative protocol to initiate high-frequency oscillatory ventilation: an experimental study. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2007; 10:R138. [PMID: 16999870 PMCID: PMC1751068 DOI: 10.1186/cc5052] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2006] [Revised: 09/04/2006] [Accepted: 09/25/2006] [Indexed: 11/10/2022]
Abstract
INTRODUCTION The objective was to study the effects of a novel lung volume optimization procedure (LVOP) using high-frequency oscillatory ventilation (HFOV) upon gas exchange, the transpulmonary pressure (TPP), and hemodynamics in a porcine model of surfactant depletion. METHODS With institutional review board approval, the hemodynamics, blood gas analysis, TPP, and pulmonary shunt fraction were obtained in six anesthetized pigs before and after saline lung lavage. Measurements were acquired during pressure-controlled ventilation (PCV) prior to and after lung damage, and during a LVOP with HFOV. The LVOP comprised a recruitment maneuver with a continuous distending pressure (CDP) of 45 mbar for 2.5 minutes, and a stepwise decrease of the CDP (5 mbar every 5 minute) from 45 to 20 mbar. The TPP level was identified during the decrease in CDP, which assured a change of the PaO2/FIO2 ratio < 25% compared with maximum lung recruitment at CDP of 45 mbar (CDP45). Data are presented as the median (25th-75th percentile); differences between measurements are determined by Friedman repeated-measures analysis on ranks and multiple comparisons (Tukey's test). The level of significance was set at P < 0.05. RESULTS The PaO2/FiO2 ratio increased from 99.1 (56.2-128) Torr at PCV post-lavage to 621 (619.4-660.3) Torr at CDP45 (CDP45) (P < 0.031). The pulmonary shunt fraction decreased from 51.8% (49-55%) at PCV post-lavage to 1.03% (0.4-3%) at CDP45 (P < 0.05). The cardiac output and stroke volume decreased at CDP45 (P < 0.05) compared with PCV, whereas the heart rate, mean arterial pressure, and intrathoracic blood volume remained unchanged. A TPP of 25.5 (17-32) mbar was required to preserve a difference in PaO2/FIO2 ratio < 25% related to CDP45; this TPP was achieved at a CDP of 35 (25-40) mbar. CONCLUSION This HFOV protocol is easy to perform, and allows a fast determination of an adequate TPP level that preserves oxygenation. Systemic hemodynamics, as a measure of safety, showed no relevant deterioration throughout the procedure.
Collapse
Affiliation(s)
- Jens Karmrodt
- Department of Anesthesiology, Johannes Gutenberg-University, Langenbeckstraße 1, D-55101 Mainz, Germany
| | - Matthias David
- Department of Anesthesiology, Johannes Gutenberg-University, Langenbeckstraße 1, D-55101 Mainz, Germany
| | - Shying Yuan
- Department of Anesthesiology, Johannes Gutenberg-University, Langenbeckstraße 1, D-55101 Mainz, Germany
| | - Klaus Markstaller
- Department of Anesthesiology, Johannes Gutenberg-University, Langenbeckstraße 1, D-55101 Mainz, Germany
| |
Collapse
|
29
|
Hess DR. Monitoring during mechanical ventilation. Paediatr Respir Rev 2006; 7 Suppl 1:S37-8. [PMID: 16798590 DOI: 10.1016/j.prrv.2006.04.177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Dean R Hess
- Harvard Medical School, Massachusetts General Hospital, Boston, MA, USA.
| |
Collapse
|
30
|
Talmor D, Sarge T, O'Donnell CR, Ritz R, Malhotra A, Lisbon A, Loring SH. Esophageal and transpulmonary pressures in acute respiratory failure. Crit Care Med 2006; 34:1389-94. [PMID: 16540960 PMCID: PMC2278169 DOI: 10.1097/01.ccm.0000215515.49001.a2] [Citation(s) in RCA: 172] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVE Pressure inflating the lung during mechanical ventilation is the difference between pressure applied at the airway opening (Pao) and pleural pressure (Ppl). Depending on the chest wall's contribution to respiratory mechanics, a given positive end-expiratory and/or end-inspiratory plateau pressure may be appropriate for one patient but inadequate or potentially injurious for another. Thus, failure to account for chest wall mechanics may affect results in clinical trials of mechanical ventilation strategies in acute respiratory distress syndrome. By measuring esophageal pressure (Pes), we sought to characterize influence of the chest wall on Ppl and transpulmonary pressure (PL) in patients with acute respiratory failure. DESIGN Prospective observational study. SETTING Medical and surgical intensive care units at Beth Israel Deaconess Medical Center. PATIENTS Seventy patients with acute respiratory failure. INTERVENTIONS Placement of esophageal balloon-catheters. MEASUREMENTS AND MAIN RESULTS Airway, esophageal, and gastric pressures recorded at end-exhalation and end-inflation Pes averaged 17.5 +/- 5.7 cm H2O at end-expiration and 21.2 +/- 7.7 cm H2O at end-inflation and were not significantly correlated with body mass index or chest wall elastance. Estimated PL was 1.5 +/- 6.3 cm H2O at end-expiration, 21.4 +/- 9.3 cm H2O at end-inflation, and 18.4 +/- 10.2 cm H2O (n = 40) during an end-inspiratory hold (plateau). Although PL at end-expiration was significantly correlated with positive end-expiratory pressure (p < .0001), only 24% of the variance in PL was explained by Pao (R = .243), and 52% was due to variation in Pes. CONCLUSIONS In patients in acute respiratory failure, elevated esophageal pressures suggest that chest wall mechanical properties often contribute substantially and unpredictably to total respiratory impedance, and therefore Pao may not adequately predict PL or lung distention. Systematic use of esophageal manometry has the potential to improve ventilator management in acute respiratory failure by providing more direct assessment of lung distending pressure.
Collapse
Affiliation(s)
- Daniel Talmor
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA, USA
| | | | | | | | | | | | | |
Collapse
|
31
|
Fernández-Pérez ER, Hubmayr RD. Interpretation of airway pressure waveforms. Intensive Care Med 2006; 32:658-9. [PMID: 16550375 DOI: 10.1007/s00134-006-0108-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2005] [Accepted: 02/13/2006] [Indexed: 11/29/2022]
Abstract
Most mechanical ventilators display tracings of airway pressure (Paw) volume (V) and flow (V). In volume preset modes, Paw informs about the mechanical properties of the respiratory system and about the activity of respiratory muscles acting on the system. When monitoring ventilator waveforms, it is important to appropriately scale the tracing so that nuances in time profiles may be appreciated. In this short monograph, we offer three examples of how clinicians may use this information for patient assessment and care.
Collapse
|
32
|
Washko GR, O'Donnell CR, Loring SH. Volume-related and volume-independent effects of posture on esophageal and transpulmonary pressures in healthy subjects. J Appl Physiol (1985) 2005; 100:753-8. [PMID: 16306256 DOI: 10.1152/japplphysiol.00697.2005] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ventilator management decisions in acute lung injury could be better informed with knowledge of the patient's transpulmonary pressure, which can be estimated using measurements of esophageal pressure. Esophageal manometry is seldom used for this, however, in part because of a presumed postural artifact in the supine position. Here, we characterize the magnitude and variability of postural effects on esophageal pressure in healthy subjects to better assess its significance in patients with acute lung injury. We measured the posture-related changes in relaxation volume and total lung capacity in 10 healthy subjects in four postures: upright, supine, prone, and left lateral decubitus. Then, in the same subjects, we measured static pressure-volume characteristics of the lung over a wide range of lung volumes in each posture by using an esophageal balloon catheter. Transpulmonary pressure during relaxation (PLrel) averaged 3.7 (SD 2.0) cmH2O upright and -3.3 (SD 3.2) cmH2O supine. Approximately 58% of the decrease in PLrel between the upright and supine postures was due to a corresponding decrease in relaxation volume. The remaining 2.9-cmH2O difference is consistent with reported values of a presumed postural artifact. Relaxation volumes and pressures in prone and lateral postures were intermediate. To correct estimated transpulmonary pressure for the effect of lying supine, we suggest adding 3 cmH2O (95% confidence interval: -1 to +7 cmH2O). We conclude that postural differences in estimated transpulmonary pressure at a given lung volume are small compared with the substantial range of PLrel in patients with acute lung injury.
Collapse
Affiliation(s)
- George R Washko
- Department of Anesthesia and Critical Care, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
| | | | | |
Collapse
|
33
|
Baba R, Paramesh K, Zwaal JW. Protective ventilation of patients with acute respiratory distress syndrome. Br J Anaesth 2004; 93:153; author reply 153. [PMID: 15192007 DOI: 10.1093/bja/aeh573] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
34
|
Sprung J, Bourke DL. Is There a Need for a Recruiting Strategy in Morbidly Obese Patients Undergoing Laparoscopic Surgery? Anesth Analg 2004; 98:268-269. [PMID: 14693639 DOI: 10.1213/01.ane.0000077691.55641.dc] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|